Integral imaging is a technique for displaying images in relief. It is considered to be particularly promising in the development of 3D television, in particular because it offers a total parallax, as opposed to a stereoscopic image display.
An integral image conventionally comprises a large number of basic images that represent the different angles of a scene in three dimensions. The compression of an integral image therefore amounts to compressing all of the elemental images.
A known method for compressing integral images involves using the MPEG-4 AVC video format to encode each of the elemental images of an integral image. Such a method is relatively direct, because it simply involves processing the integral images as a traditional video sequence.
A drawback of such a method lies in the fact that the spatial and temporal redundancy is reduced indiscriminately. The specific form of integral images, according to which elemental images are likely to present numerous spatial and temporal redundancies between one another, is therefore not exploited optimally.
A more efficient method for compressing integral images without moving outside the MPEG-4 AVC standard involves reorganizing the elemental images. This enables the redundancies between elemental images to be exploited, but lots of redundant information remains unexploited, in particular the significant correlation between the elemental images of a current integral image and the corresponding elemental images of adjacent integral images.
Another known method involves encoding integral images using a 3D-DCT compression algorithm, as described in the document R. Zaharia, A. Aggoun, M. McCormick, ‘Adaptive 3D-DCT compression algorithm for continuous parallax 3D integral imaging’, Signal Processing: Image Communication 17 (2002) 231-242. This method is relatively close to the aforementioned methods based on the MPEG-4 AVC standard. Indeed, the reorganization of the elemental images is identical. The difference between this other known method and the aforementioned methods lies in the encoding structure of image sequences. This method undoubtedly improves the compression of integral images, but does not enable the redundancies characteristic of integral images to be reduced.